- move issubtype and isgenerictype from transform.py to toolkit.py

DHParser/toolkit.py

@@ -24,6 +24,7 @@ so that they are best defined in a toolkit-module.
 
 import codecs
 import hashlib
+import inspect
 import io
 import parser
 
@@ -45,6 +46,8 @@ __all__ = ('escape_re',
            'escape_control_characters',
            'is_filename',
            'lstrip_docstring',
+           'issubtype',
+           'isgenerictype',
            'load_if_file',
            'is_python_code',
            'md5',
@@ -101,6 +104,34 @@ def is_filename(strg: str) -> bool:
     #   and strg.select('*') < 0 and strg.select('?') < 0
 
 
+#######################################################################
+#
+# type system support
+#
+#######################################################################
+
+
+def issubtype(sub_type, base_type):
+    if sys.version_info.major <= 3 and sys.version_info.minor <= 6:
+        return issubclass(sub_type, base_type)
+    try:
+        base_type = base_type.__origin__
+    except AttributeError:
+        pass
+    try:
+        mro = inspect.getmro(sub_type)
+    except AttributeError:
+        mro = []
+        for t in sub_type.__mro_entries__([sub_type]):
+            mro.extend(inspect.getmro(t))
+    # print(" " if base_type in mro else "!", base_type, sub_type, mro)
+    return base_type in mro
+
+
+def isgenerictype(t):
+    return str(t).endswith(']')
+
+
 #######################################################################
 #
 # loading and compiling

DHParser/transform.py

@@ -33,7 +33,7 @@ from functools import partial, reduce, singledispatch
 
 from DHParser.error import Error
 from DHParser.syntaxtree import Node, WHITESPACE_PTYPE, TOKEN_PTYPE, MockParser, ZOMBIE_NODE
-from DHParser.toolkit import expand_table, smart_list, re, typing
+from DHParser.toolkit import issubtype, isgenerictype, expand_table, smart_list, re, typing
 from typing import AbstractSet, Any, ByteString, Callable, cast, Container, Dict, \
     Tuple, List, Sequence, Union, Text, Generic
 
@@ -150,29 +150,6 @@ def transformation_factory(t1=None, t2=None, t3=None, t4=None, t5=None):
             does not have type annotations.
     """
 
-    def issubtype(sub_type, base_type):
-        # Because of changes in thy typing system, the following doesn't
-        # work any more in Python 3.7:
-        #
-        #     return base_type in inspect.getmro(subtype)
-        #
-        # Therefore it has all gotten a bit more complicated...
-        try:
-            base_type = base_type.__origin__
-        except AttributeError:
-            pass
-        try:
-            mro = inspect.getmro(sub_type)
-        except AttributeError:
-            mro = []
-            for t in sub_type.__mro_entries__([sub_type]):
-                mro.extend(inspect.getmro(t))
-        print(" " if base_type in mro else "!", base_type, sub_type, mro)
-        return base_type in mro
-
-    def isgenerictype(t):
-        return str(t).endswith(']')
-
     def type_guard(t):
         """Raises an error if type `t` is a generic type or could be mistaken
         for the type of the canonical first parameter "List[Node] of

test/test_toolkit.py

@@ -21,13 +21,14 @@ limitations under the License.
 """
 
 import concurrent.futures
+import collections.abc
 import os
 import sys
 
 sys.path.extend(['../', './'])
 
 from DHParser.toolkit import has_fenced_code, load_if_file, re, \
-    lstrip_docstring
+    lstrip_docstring, issubtype, isgenerictype, typing
 from DHParser.log import log_dir, logging, is_logging
 
 
@@ -150,6 +151,12 @@ class TestStringHelpers:
                                          'indented line'
 
 
+class TestTypeSystemSupport:
+    def test_issubtype(self):
+        assert issubtype(typing.List, typing.List)
+
+
+
 if __name__ == "__main__":
     from DHParser.testing import runner
     runner("", globals())